1. Field of the Invention
The invention relates to a piggyback equipment panel, and a device for and a method of attaching the piggyback panel (which itself may contain multiple payloads) as a secondary payload. The affixed instrument package or the like, (as a secondary payload) is mounted on the nadir end of the primary satellite, preferably employing a universal adapter between the primary satellite and the hosted piggyback equipment panel (which contains at least one secondary payload).
2. Background of the Invention
In order to increase the number of payloads that can be flown with reduced costs, the concept of “hosted hardware” was developed, which infers that a parent spacecraft “host” is used as a platform on which the “hosted payload” can achieve access to space. The hosted payload may be a micro-satellite (subject of previous patent application) or a collection of sensors, electrical units and antenna. There are two primary ways to accomplish this task, integrating the payload into the parent satellite or integrating the payload onto the parent satellite. One approach to integrating the payload into the parent satellite involves “significant-integration,” where the payload hardware is installed during the manufacturing of the primary/“parent” spacecraft. Units are mounted directly on internal equipment shelves and spacecraft subsystems are redesigned to accommodate the specific needs of the hosted hardware. An example of this approach is the GCCS FAA payload integrated on Intelsat's Galaxy 15 spacecraft manufactured at Orbital Sciences. The disadvantage of this approach is that the flight hardware must be available in time for the assembly and test of the parent spacecraft and the non-recurring costs are high due the spacecraft redesign which must be conducted. The hosted hardware rides on the parent satellite—utilizing the parent satellite bus for power, thermal control and orbital maintenance (attitude control (pointing), station keeping and momentum dumping).
The approach of mounting a hosted payload onto the parent spacecraft offers several advantages, including: little non-recurring work is required, hardware (such as a micro-satellite or equipment platform) can arrive later in the program, rework of the hosted payload is much easier and switch-out of one hosted payload for another is relatively simple. To this end, several standardized Multiple Payload Adapters (MPA's) have been developed to attach to existing payload for taking advantage of the excess payload capability on launch systems.
Key to achieving the goal of flexible and inexpensive access to space is the development of standardized adapter interface (ESPA, SIV, SET) as a standard part of the spacecraft generic design. This generic interface could be utilized for either carrying small satellites, carrying a hosted equipment panel, or (if required by the parent satellite communications subsystem) an antenna feed tower. One of the advantages of hosting a secondary payload on this generic interface is that if the microsat or equipment panel becomes unavailable, the parent satellite can be flown without the secondary payload (where electrical connectors caps and thermal blankets are used to close out the open nadir position). Since the equipment panel requirements include an envelope of acceptable mass properties, if the nadir location is depopulated late in the program, a dummy mass model need not be flown to maintain parent spacecraft mass properties limitations.
Thus, there is a need to reduce the cost and increase the ease and frequency of taking small payloads into orbit. Piggybacking a secondary payload onto the nadir of a parent/primary telecommunications satellites through the use of a standardized or universal adapter is an improved and novel method of achieving this task. Herein, the terms “primary payload” and “primary satellite” are used interchangeably, but the secondary payload may be a satellite, an instrument package, antenna cluster or the like.
Thus, it is an aspect of the present invention to overcome the problems and disadvantages of the prior art designs and methods.
It is yet another aspect of the present invention to provide a payload design that permits the use of a universal adapter for coupling together in an efficient and effective package at least one secondary payload to a primary satellite for launching the secondary payload in a certain orbit.
It is a further aspect of the present invention to provide an micro-adapter between the primary satellite and a secondary payload, which utilizes heritage/generic hardware to couple an equipment panel or antenna tower to the parent satellite nadir face (or in the case of a microsat secondary payload, also separate the microsatellite from the parent satellite at the appropriate time).